16 Part III. — Twenty-second Annual Report 



a total of 27,156 fishes in the completely recorded hauls, 22,051 were 

 marketable and 5105 unmarketable, the percentage of the former being 

 81*2, and of the latter 18*7 — the proportion of the unmarketable being 

 thus considerably under what it was on the inshore grounds. In these 

 series of hauls also all the gurnards were classed as unmarketable, while, 

 on the other hand, owing to the depth of water, all the plaice were 

 marketable. 



The proportion of cod, including codling, which was marketable was 

 77*2 per cent., 22*8 per cent, being unmarketable ; in the case of haddocks, 

 the percentage marketable was 86"7 and unmarketable 13*3; while with 

 whitings the respective proportions were 54'4 and 45*6 per cent. 



The Proportion of Immature Fish Landed, 



The information given above and detailed in the Tables as to the pro- 

 portion of fish of the different kinds which are caught in the operations 

 of commercial trawl-fishing and thrown away as unmarketable, enables an 

 opinion to be formed as to the degree of destruction which may take 

 place on the inshore grounds. 



It is also of some importance to be able to ascertain the proportion of the 

 fish caught and landed which are immature, that is to say, which have never 

 developed milt or roe and reproduced their species. In most cases it 

 may be said that the greater proportion of the unmarketable individuals 

 of the class which is unmarketable owing to the small size, are immature, 

 although in some instances mature fishes may also be too small to be 

 marketable. This is the case with the common dabs, none of the imma- 

 ture individuals being large enough to be marketable, and those landed 

 are therefore adult fishes which have either reproduced or are large 

 enough to reproduce. The same is true of the flounder, which, however, 

 is not taken often in the trawl in ordinary commercial fishing. It is also 

 true to some extent of the haddock, and still more of the whiting, com- 

 paratively few of these under the size at which maturity may be reached 

 being brought to market, and with the whiting, at all events, there is no 

 doubt that a fairly large proportion of the smaller-sized but mature 

 individuals are rejected because of their small size. 



With plaice, on the other hand, as with turbot, brill, and halibut, all 

 those which have arrived at the size of maturity, and a large number 

 which are under that limit are eminently marketable. It is the same 

 with the cod and the large round fishes, and it is thus of some importance 

 to be able to show approximately the proportion of the mature and 

 immature fishes of the different species which are under ordinary circum- 

 stances brought to market. 



In order to do this it is necessary to obtain two classes of facts — the 

 limit of size which separates the mature from the immature in the 

 different kinds of fish, and the numbers of fish at the various sizes which 

 are caught. Information on the former head, as I have elsewhere pointed 

 out, is not as exhaustive as one would like, but, still, numerous observa- 

 tions have been made in Scotland and other countries which enable one 

 to differentiate, sometimes with precision and at other times broadly, the 

 mature from the immature. It happens, however, at all events in the 

 case of some fishes, that the size which separates the mature from the 

 immature is not the same in all places. Thus, with plaice the limit 

 between the mature and immature is higher in the northern parts of the 

 North Sea than the southern parts and the Channel. This difference 

 does not, however, affect the present investigation to any extent, because 

 comparatively a very small proportion of the fish landed at Aberdeen is 



